Spring return push door with door lock



May 6, 1947. J. R. NEWKIRK SPRING RETURN PUSH DOOR WITH DOOR LOCK FiledFeb. 27, 1945 3 Sheets-Sheet 1 M m m T WN NE R EN V. n M M Q OY J |.l

m MN g k May 6, 1947. J. R. NEWKIRK SPRING RETURN PUSH DOOR WITH DOORLOCK Filed Feb. 27, 1945 5 Sheets-Sheet 2 i RK Y 3%. N R EN 0 V W m y1947 J. R. NEWKIRK 19,964

SPRING RETURN PUSH DOOR WITH DOOR LOCK Filed Feb. 27, 1945 3Sheets-Sheet 5 '2 I": R P- a R U- I nrl I I I a I INVENTOR JOHN R.NEWKIRK avcb zfg x ATTORN 5Y5 Patented May 6, 1947 SPRING RETURN PUSHDOOR WITH DOOR LOCK John R. Newkirk,

tional Pneumatic Company,

Railway, N. J a-ssignor to Na- New York, N. Y., a

corporation of West Virginia Application February 27, 1945, Serial No.579,971

14 Claims.

This invention relates to a door operating mechanism for the rear doorsof motor buses, street cars and the like.

The main object of this invention is to provide an automaticallyoperating lock for a door operating apparatus of the type disclosed inmy United States Patent No, 2,259,579, granted tober 21, 1941,

Other and more detailed objects of this invention will be apparent fromthe following description when taken in connection with the attacheddrawings, and as defined in the appended claims.

This invention resides substantially in the combination, construction,arrangement and relative location of parts, all as will be described indetail below.

In the accompanying drawings,

Figure 1 is an elevational view of the mechanism of this invention,showing the upper portion of a rear door, looking at the mechanism fromthe inside of the vehicle to which it is applied, with the apparatus indoor closed position;

Figure 2 is a top plan view of this mechanism with the parts in doorclosed position;

Figure 3 is a top plan view of the mechanism with the doors in fullyopened position, showing that the doors open outwardly of the vehicle;

Figure 4 is an enlarged end elevational view of the lock structure withsome parts broken away;

Figures 5 and 6 are top plan and side elevational views of a structuraldetail comprising the mounting bracket for the lever of Figures '7 andFigures '7 and 8 are top plan and side elevational views of the levermechanism for interconnecting the door shafts with the spring returnmotor for closing the doors; and

Figure 9 is a diagrammatic and schematic view illustrating one mode ofoperation of the ap- Daratus.

The subject matter of this invention is for use on so-called one-manoperated vehicles such as motor buses, street cars, and the like, onwhich boarding and alighting facilities are provided which include aso-called rear door exit remotely positioned with respect to the vehicleoperator, and, therefore, not under his close observation. The subjectmatter of this invention is related to of the vehicle, the motive powercontrol for the vehicle and/or the brake for the vehicle, so that 2 thedoor is locked in closed position and unlocked when the vehicle is atrest.

It is common practice today to employ, and the subject matter of thisinvention is concerned with, a rear door operating mechanism of the typeby which, when the door is unlocked, the door may be pushed open by a prson desiring to leave the vehicle. The act of pushing the door openloads a spring return motor which returns the door to closed positionafter the alighting passenger releases it. It is usual, in such asystem, to provide a mechanism for automatically locking the doors inclosed position, after they are returned to that state by the springreturn motor.

Such a ystem is disclosed in my above mentioned patent, as here.However, the said patent does not include, as does this disclosure, amechanism for preventing the doors from being inadvertently opened, andthereby creating the possibility of an accident should a person beleaning against the doors when they are unlocked by an act of thevehicle operator of the type above described. In the system of mypatent, when the doors are unlocked by such an act of the vehicleoperator, they can swing open if a passenger is leaning against them,tending to tumble him into the street. My herein disclosed improvementprevents the doors from opening if anyone is leaning against them, butleaves them free to be pushed open if, at the time they are unlocked,there is no pressure on them.

In order to have a full understanding of the improvement hereindisclosed, a considerable portion of the mechanism of my above mentionedpatent has been duplicated, although there is some rearrangement of theelements thereof.

The detailed embodiment of the invention as illustrated in the attacheddrawings will now be described. The mechanism of Figure 1 is inelevation as viewed from the inside of the vehicle. The support or plateI comprises a part of the vehicle body structure or a special supportmounted therein above the rear door opening. Mounted upon this supportis a plate 2 for in turn supporting the various elements of the combination of this invention. A pair of bearings and 6 are mounted on theplate 2 and are posi-- tioned to provide rotatable supports for theupper ends of the pintles 5 and 6 attached to the upper corners of thedoor leaves 1 and 8 which are similarly supported at the bottom in thefloor or doorstep well. Thus the door leaves I and 8 may rotate abouttheir outer vertical edges, from the door closed position shown inFigure 2, to the door open position of Figure 3, by swinging outwardlyof the vehicle body. On the outer face of the door leaf 1 near the topedge, is a plate or bar 9 secured thereto so as to project beyond itsfree edge and overlie for a short distance the outer face of the doorleaf 8, as indicated by the portion 9' thereof. If desired, a similarbar can be used at the bottom of the. door leaves, attached to the leaf1 and overlying the leaf 6. The function of this bar will be describedlater.

Secured to the upper ends of the pintles and 6, in any suitable manner,are the short levers Ill and I I respectively which in turn arepivotally connected to the links I2 and I3 respectively. The free endsof the links l2 and I3 are pivotally connected to the ends of ateetering bar I I which forms part of a single casting clearlyillustrated in detail in Figures 7 and 8. The teetering bar US isprovided with pivot pins, as shown, on which the ends of the links i2and I3 are pivotally mounted.

The compound lever structure or single casting of Figures '1 and 8 ispivotally mounted on a pivot pin I5, which is inturn mounted in a plateIt. attached to the base plate 2. This structure is clearly illustratedin Figures 5 and 6. The unitary lever casting includes. in addition tothe teetering bar I4 the lever II extending at right an les thereto, thelever i8 extending at an acute angle thereto and having a lateralprojection I9. Thelever 18 has mounted therein apivot pin 211. Thesevarious levers are united by a hub which is rotatably mounted onthepivot pin I5.

The end of a piston. rod H is pivotally connected with pin 2U. Rod 2Iextends into a cylinder 22 which is pivotally mounted, at one end, on a.pivot pin. 23 (see Fig. 1), in turn mounted on the base plate 2. Withinthe cylinder 22 is apiston 24, and between. it and the end capthroughwhich the pistonrod 2i slides is a suitably proportionedcompressionspring 25. Spring 25 is related to piston 2A to move it inthe door closing, direction. The. cap at the end 01 the cylinder 22.oppositethe spring-retaining cap is.

provided with an adjustable air escape port 2] to cushionorcontroltherate ofreturn movement. of the piston 26 under the action ofspring 25 in the door closing direction.

Mounted onv the base. plate 2 isa bracket. 28 to whichis securedalocking cylinder 29 within which, as shown, is. a piston 3| attached toa piston rod 33'. A spring 32 lies betweenthe piston and the end of thecylinder to resist the movement of the piston in air operated direction.A compressed air supply pipe 30 from any suitable source supplies air tothe locking cylinder 29, as will be described later.

Adjust-ably secured to the projecting end of the locking cylinderpistonrod 33 is a clevis 34 on which in turn a collar 36 ismounted andlocked thereon by means of aset screw such as an Allen screw 38. As isclear from Figure 2,.the piston rod 33 has a reduced threaded end whichis received in a threaded recess in the end of the clevis 34 and islocked in adjusted position by means of a lock out 35. The collar 36 hasa pair of radially opposedpivot pins 11 which cooperate with a yoke 48which will be referred to later.

The clevis 34 has an. opening therethrough shaped as indicated by thedottedllines in Figure 2; the. lever I'I,.lies. in the position of theparts inFlg. 2, and extends into that opening. In that position, alateral projection. 19 on the lever I8 cooperates with. an adjustablestop screw 28 mounted on the plate IB (see Figs. 5 and 6) Leo Us) ver Hhas a vertical projection on its end face (see Fig. 1), which cooperateswith an adjustable machine screw 41 mounted on a lever 42 pivotallymounted at 43 on a bracket on the base plate 2. Mounted adjacent thislever is a microswitch with its operating member projecting downwardly(see Fig.1.) for cooperation with an L-shaped extension as forming partof the. lever 42. A compression spring 44 normally urges the lever 42 ina clockwise direction, which is the direction to close the microswitch40. When the door is in closed and locked position, however, the lip onthe lower face of the lever I1, through engagement with the screw M,holds lever 42 in retracted position, comprising spring 44 so thatmicroswitch is open.

The yoke 45 previously referred to is pivotally mounted on a pivot pint! in a support on the baseplate 2. The yoke 45 includes a laterallyextending lever which is pivotally connected at 49 to a link 5!! (seeFig. 4), which in turn is pivotally connected by pivot pin 5| operatingin elongated slot 53 formed in the lateral extension of the lockinglever 52. The lever 52 is pivotally mounted at 51 on the underside ofthe support I. At this point it may be noted that Figure 4 should berotated in a clockwise direction through an angle of 90 degrees toposition it in conformity with the other figures. Thus, in Figure 4, oneis looking towards the free edge of the door leaf 1; and the lockinglever 52 extends generally parallel to the floor or root of the vehicle,that is, at right angles to the top edge of the door. A spring {it liesbetween the lever 52 and the adjacent part of the vehicle body formed soas to normally urge the lever 52 in a'counierclockwise direction (Fig.ll. Mounted near the upper right hand corner (Fig. 1) of door I is a rod56 (Fig. 4) having the hooked end for movement with the end M of thelever 52. It might be noted that Figure 4 shows the position of the.parts'with the doors closed, but with no pressure such as would. resultfrom a personleaning against the doors.

The structure of Figure 9 will be briefly described. It illustrates theuse of the subject matter of this invention with the control system forthe front door engine DE which is of the differential type. Pressurefluid. from any suitable source is supplied through. the pipe 10 whichincludes a shut-cit valve H and an air strainer 12, to the engine DE ata point between the two pistons thereof in accordance with usualpractice. in this respect, and. as illustrated in the above mentionedpatent.

' Pressure fluid is also supplied from pipe I3 through a branch 14 tothe door control valve CV. A pipe 15 extends from this valve to thelarger cylinder on the engine DE. The pipe 'ldis the exhaust pipe andthe pipe as also extends from this valve to the. door locking cylinder29; The microswitch 4B is connected to the positive side of a suitablygrounded. current source, and to the brake interlock magnet valve 11having one terminal grounded. The current supply leadfor the magnetvalve is also connected to agrounded signal light I8 which light ispositioned adjacent the vehicle operators station.

In order to understand a description. of the operation of this system itwill be understood that the mechanismas showniniignrez willhe in. theposition illustrated therein when the doors are closed and locked. Thedoors are. locked in closed position by reason of the fact that theteetering bar I4 and the links I2 and I3 all lieirr a straight lineforming a locking-toggle: linkage:

system. This position of these parts is assured by the fact that uponthe previous closing of the doors the spring 25 acts to move theteetering bar M in a clockwise direction until the projection or lug l9engages the adjustable stop screw 25, in which position it is shown inFigure 2. The compression spring 25 in the cylinder 22 is urging theparts in this direction so that the teetering bar I 4 is held in lookingposition in cooperation with the stop screw 26. At this time pressurefiuid is being supplied to cylinder 29 through the pipe 30, so that theclevis 34 is in the position shown in Figure 2.

Referring to Figure 9, pressure fluid is supplied from the sourcethrough pipe 10, branch 14 and through the valve CV to pipe 30,communication between branch 14 and pipe 30 being established when thevalve is in the position shown. In this same position of the valve theleft hand end of the large cylinder of the differential engine DE isconnected through pipe 15 and valve CV to branch 14. Pressure fluid, ofcourse, is supplied continuously from pipe 10 through the pipe 13 to theright hand end of the engine in accordance with usual practice, andunder these conditions the front door of the vehicle is closed.

While the front door engine as herein described is of the differentialtype, it will, of course, be apparent to those skilled in the art thatany other suitable type of air operated engine can be employed for thefront door without affecting the rear push door operation.

When the vehicle operator brings the vehicle to a stop by applyin thebrakes, he moves the operator of valve CV to a, position to disconnectpipe from branch 14 so that pressure fluid is exhausted from the lefthand end of the large cylinder of engine DE through pipe 76 to cause thefront door to open. In this position of the valve, communication betweenbranch 14 and pipe 30 is maintained, so that the rear door remainslocked. In order to unlock the rear door, the vehicle operator moves thehandle of valve CV to another position which does not disturb theconnection between branch 14 and pipe 15, but does break the connectionbetween branch 14 and pipe 30, connecting the latter to the exhaust pipe16. Thus the front door remains open and the cylinder 29 is exhausted.Spring 32 in this cylinder pushes piston 3! to the right, carryingclevis 34 with it. This clevis engages the lever l1 and moves it in acounterclockwise direction a short distance. so that the teetering barit is moved out of the straight line alignment with the links l2 and I3.The rear door leaves 1 and 8 are then normally free to be pushed open byhand so that a passenger may alight. As these door leaves are pushedopen, spring 25 is compressed, and when the door leaves are released bythe alighting passenger, spring 25 rotates the teetering bar M in aclockwise direction back to door closed position. This return movementis cushioned by the adjustable air exhaust port or speed plug 21.

-It will be seen that if one or more passengers are leaning against thedoor leaves I and 8, when the locking cylinder 29 is open to exhaust sothat the teetering bar 14 is moved out of alignment. without someprovision for preventing it, the doors will push open and the passengersmight easily fall out of the vehicle and be injured. This accidentaloperation is prevented by means of the locking arrangement shown inFigures 4 and 5.

At the time the cylinder 29 is open to exhaust so that its piston 3|moves to the right, carrying piston rod 33 and clevis 34 with it, itwill be seen (Fig. 1) that the L-shaped lever 46 extension will berotated in a clockwise direction, tending to rotate lever 52 (Fig. 4) ina. clockwise direction, and move its end 54 out of the path of thehooked end 55 of the latching rod 56. However, it will be equallyapparent that if someone is leaning against either of the door leaves 7and 5, they will spring outwardly so that the hooked end 55 engages theend 54 of the lever 52. Thus the locking cylinder 29 cannot move farenough to cause the clevis 34 to engage the lever ll. Thus the doorremains locked in closed position as long as this pressure is maintainedon either of the leaves I and 8.

At this point it may be noted that pressure on leaf 8 has the sameeffect as pressure on leaf 1 because of the plates 9. If there is nopressure on either door leaf at the time that cylinder 29 is exhausted,the lever 52 will be moved in a clockwise direction out of the path ofmovement of the hooked end 55 (see Fig. 4), so that the operation ofdoor opening as previously described may proceed in a normal manner. Itwill also be apparent that if there was pressure on the door at the timethe cylinder 29 is exhausted, so that hooked end 55 engages end 54, thatcondition can be corrected simply by relieving the pressure on the door.The spring in the locking cylinder is continuing to tend to causeclockwise rotation of the lever 52, so that as soon as the pressure istaken oil of either or both of the door leaves I and 8, they will springback enough so that the hooked end 55 will release the cooperating end54 of the lever 52 and it will be pulled to the left (Fig. 1). The doorsmay then be pushed open by hand.

As soon as the teetering bar l4 begins to move towards door openposition the depending lug of lever I1 moves away from the adjustablescrew 4!, so that spring 44 can cause counterclockwise movement of leverextension 45 and close microswitch 45. As will be seen from Figure 9,the closing of microswitch 40 completes the circuit for the brakeinterlock magnet valve I1, so that air will be supplied directly to thebrakes through the magnet valve to keep them applied even if the vehicleoperator tries to release them. At the same time signal light 18 isenergized, so that the operator knows the rear door is not closed andlocked. It will be seen that the microswitch opens just as the rear doorgoes into fully closed and locked position, extinguishing the signallight and releasing the brake interlock, so that the vehicle is free tomove.

The vehicle operator may close the front door at any time by moving thevalve CV back to its original position, connecting pipe 15 to branch 14.At the same time air is applied to the cylinder 29 to return theconnected parts to the position shown in Figures 1 and 2. This can occureven though the rear doors are still open, since lever I! can swing intothe position shown in Figure 2, with the clevis 34 in the positionillustrated. At the same time, the mechanism, including the lever 52,returns to normal position shown in the various figures. This does notinterfere with the closing of the rear doors because, as they move toclosed position, the hooked or looking rod 56 engages the inclined faceof lever 52 and forces it to the left (Fig. 4) against spring 60 so thatthe hooked end may pass back to the position shown in Figure 4. Theslotted connection 53 is provided for this purpose, that is, to permitlever 52 to move to the lelt, even though the link 50 is held rigidly inthe position shown in Figure 4, the assumption having been made, ofcourse, that air is back on the locking cylinder 25. Spring 50 snaps thelocking lever 52 back to normal position as the hooked end 55 passes offof the end of the locking lever.

Thus it will be seen that no condition can be created by the vehicleoperator which will prevent the closin of the rear doors and the returnof all parts to normal position. An important point, however, is thatthe rear doors may not inadvertently open under the weight of apassenger and throw him to the ground when the vehicle operator performshis normal operations of opening the front door and conditioning therear door operating apparatus for opening these doors.

From the above description it will be apparent to those skilled in theart that the subject matter of this invention may be embodied in otherphysical forms, and I do not, therefore, desire to be strictly limitedto the disclosure as given herein for purposes of illustration, butrather to the scope of the invention as defined in the appended claims.

What is claimed is:

1. In a door operating system, the combination including a door, amotive device for closing the door, a linkage system connecting themotive device with the door, said linkage system taking a. position tolock the door when closed, motive means for moving the linkage system tounlocking position, said doors being then free to be pushed open, andmeans for preventing opening movement of the doors if they are underpressure when the linkage system is moved to unlocking position.

2. In the combination of claim 1, said means for preventing opening ofthe doors including a lever pivotally mounted adjacent the door and acooperating member mounted on the door.

3. In the combination of claim 1, said means for preventing opening ofthe doors including a lever pivotally mounted adjacent the door and acooperating member mounted on the door, and means interconnecting saidplvotally mounted lover with said motive means to move it out of lockingposition if the doors are free of pressure when the linkage system ismoved to unlocking position.

4. In a push door system of the type described, the combinationincluding a pivotally mounted door, a motive device connected to thedoor for moving it to closed position while leaving it free to be pushedopen, a linkage system connecting the motive device with the door andlocking it in closed position, motive means for moving the linkagesystem out of locking position to release the door for opening movement,and means for preventing opening movement of the door if it is underpressure when so released.

5. In the combination of claim a, said last means being actuated by saidmotive means to release the door for opening movement under its ownpressure at that time.

6; In combination with a door, means tending to move the door to closedposition, means for locking the door against movement out of closedposition, and means for disabling the door looking means, the door, whenthe locking means is disabled. bein movable by pressure directlythereagainst, and means for preventing such disabllng if the pressureagainst the door was ob fec'tlve simultaneously with the energization ofthe disabling means.

7. In combination with a door, means tending to move the door to closedposition, means Ior locking the door against movement out of closedposition, and means for disabling the door looking means, the door, whenthe locking means is disabled, beingmovable by pressure directlythereagainst to open the door against the action or the means tending tomove the door to closed position, and means for preventing suchdisabling if the pressure against the door was effective simultaneouslywith the energization of the disabling means.

8. In combination with a door, means tending to move the door to closedposition including a linkage, the linkage including means for lockingthe door against movement out of closed position, and means for movingthe linkage to disable it as door locking means, the door, when thelocking means is disabled, being capable of being opened by pressuredirectly thereagainst and in opposition to the action of the meanstending to move the door to closed position, and means for preventingsuch disabling if the pressure against the door was effectivesimultaneously with the en ergization of the disabling means.

9. In combination with a door, a lever for moving the door to open andclosed positions, means for actuating the lever to move the door toclosed position, the lever then assuming a position to lock the dooragainst movement out of closed position, and means for moving the leverout of locking position, the door, when the lever is not in lookingposition, being capable of being opened by pressure directlythereagainst, and means for making the lever moving means ineffective ifthe pressure against the door was effective simultaneously with theenergization of the lever moving means.

10. In combination with a vehicle having a door, control means for thevehicle, means tending to move the door to closed position, means forlocking the door against movement out of closed position, and means fordisabling the door locking means on actuation of the control means, thedoor, when the locking means is disabled, being movable by pressuredirectly thereagainst, and means for preventing such disabling if thepressure against the door was efiective simultaneously with theactuation of the control means.

11. In combination with a door, means tending to move the door to closedposition, means for locking the door against movement out of closedposition, and means for disabling the door locking means, the door, whenthe locking means is disabled, being movable by pressure directlythereagainst, and means for preventing such disabling if the pressureagainst the door was effective simultaneously with the energization ofthe disabling means and until that pressure has first been removed.

12. In combination with a vehicle having a door, control means for thedoor, an auxiliary door, means tending to move the auxiliary door toclosed position, means for locking the auxiliary door against movementout of closed position, and means for disabling the door locking meanson actuation of the control means, the auxiliary door, when the lockingmeans is disabled, being meva-bie by pressure directly thereagainst, andmeans for preventing such disabling if the pressure against theauxiliary door was ciiective simultaneously with the actuation of thecontrol means.

13. In combination with a vehicle having a door, control means for thedoor, an auxiliary door, means tending to move the auxiliary door toclosed position, means for locking the auxilary door against movementout of closed posit-ion, and means for disabling the door locking meanson actuation of the control means, the auxiliary door, when the lockingmeans is disqibled, being movable by pressure directly thereugainst, andmeans for preventing such disabling of the pressure against theauxiliary door was ef- Pective simultaneously with the actuation of theGontrol means and until that pressure has first been removed.

14. In combination with a. vehicle having a door, control means for thedoor, an auxiliary door, a lever for moving the auxiliary door to openand closed positions, means for actuating (he lever to move theauxiliary door to closed position, the lever then assuming a position tolock the auxiliary door against movement out of out of looking positionon actuation of the con- 10 trol means, the auxiliary door, when thelever is not in looking position, being capable of being opened bypressure directly thereagainst to open the auxiliary door against theaction of the means tending to move the auxiliary door to closedposition, and means for making the lever moving means ineffective ii thepressure against the auxiliary door was effective simultaneously withthe actuation of the control means and until that pressure has firstbeen removed.

JOHN R. NEWKIRK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date Krause Dec. 31, 1940 Newkirk Oct. 21,1941 Number Certificate of Correction Patent No. 2,419,964. May 6, 1947.JOHN R. NEWKIRK It is hereby certified that errors appear in the printedspecification of the above numbered patent requiring correction asfollows:

Column 4, line 15, for the word comprising read compressing; column 6,line 3, strike out the word and numeral lever 46; line 43, before theword extension strike out lever;

and that the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this 26th day of April, A. D. 1949.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

